Power plants experience damage to relief valves and to fluid dryers caused by vortex shedding coupling with an acoustic mode in standpipes and other dead end piping branches. An acoustic side branch consisting of a large cantilevered “Helmholtz resonator” has been used on standpipes in some power plants to reduce vortex shedding. However, such a modification may be difficult and expensive.
U.S. Publication No. 2008/0149201 A1 discloses a main flow line and relief valve assembly that includes a main line fitted with a standpipe and a relief valve fitted within the standpipe. A sleeve is inserted in the standpipe below the relief valve to extend into the main line for mitigating acoustic cavity resonances.